Global cognitive factors modulate correlated response variability between V4 neurons

Area of Science:

• Neuroscience
• Cognitive Science

Background:

• Cognitive factors, including attention and arousal, modulate neural responses in sensory cortex.
• Understanding how global cognitive states affect neural variability is crucial for interpreting psychophysical and physiological data.
• Global cognitive factors offer a tractable way to study the neuronal basis of cognitive modulation without complex task training.

Purpose of the Study:

• To investigate how global cognitive factors influence correlated response variability between neurons in visual cortex.
• To determine if task difficulty, as a global cognitive factor, affects neural response correlations.

Main Methods:

• Simultaneous recordings from multiple neurons in visual area V4 of rhesus monkeys.
• Monkeys performed a contrast discrimination task with block-wise changes in difficulty.
• Neural activity and behavioral performance were recorded during the task.

Main Results:

• Correlated variability between simultaneously recorded neurons decreased as task difficulty increased.
• This reduction in correlated variability occurred even when stimuli were distant from neuronal receptive fields.
• Task difficulty significantly impacted neural response correlations.

Conclusions:

• Global cognitive factors, such as task difficulty, can systematically alter correlated neural variability in sensory cortex.
• These findings suggest that global cognitive states provide a general framework for understanding cognitive influences on sensory processing.
• Studying global cognitive factors may reveal fundamental mechanisms of neural modulation by cognition.